CVE-2021-20613 : Security Advisory and Response

This article provides detailed information on CVE-2021-20613, an improper initialization vulnerability affecting MELSEC-F series FX3U-ENET Firmware version 1.16 and prior. Learn about the impact, technical details, mitigation strategies, and more.

Understanding CVE-2021-20613

CVE-2021-20613 is an improper initialization vulnerability that poses a risk to certain versions of the MELSEC-F series FX3U-ENET, FX3U-ENET-L, and FX3U-ENET-P502 firmware.

What is CVE-2021-20613?

The vulnerability in the affected firmware versions allows a remote unauthenticated attacker to trigger a denial-of-service (DoS) condition in the communication function by sending specially crafted packets.

The Impact of CVE-2021-20613

While control by MELSEC-F series PLC is not affected, system reset is required for recovery. This vulnerability could lead to service disruption and operational challenges for organizations using the impacted products.

Technical Details of CVE-2021-20613

Here are the technical specifics related to CVE-2021-20613:

Vulnerability Description

The vulnerability originates from improper initialization in the firmware versions mentioned, enabling attackers to disrupt communication and cause a DoS condition.

Affected Systems and Versions

Products impacted include MELSEC-F series FX3U-ENET, FX3U-ENET-L, and FX3U-ENET-P502 with firmware versions 1.16 and prior.

Exploitation Mechanism

Remote unauthenticated attackers can exploit this vulnerability by sending specially crafted packets, triggering the DoS condition.

Mitigation and Prevention

Protecting against CVE-2021-20613 requires immediate action and long-term security practices.

Immediate Steps to Take

Organizations should consider implementing network protections, restricting access, and monitoring for suspicious activity to mitigate the risk posed by the vulnerability.

Long-Term Security Practices

Establishing strong network security measures, keeping systems updated, and conducting regular security assessments are essential for long-term protection against potential vulnerabilities.

Patching and Updates

Vendor-released patches and firmware updates should be promptly applied to address the vulnerability and enhance the security posture of the affected systems.